WINE is definetely not an emulator. Neither a runtime. Wine is an implementation of the Windows 3.x and Win32 APIs on top of X and Unix featuring a Windows compatibility layer. Wine provides both a development toolkit (Winelib) for porting Windows sources to Unix and a program loader, allowing unmodified Windows 3.1/95/NT binaries to run under Intel Unixes (some screenshots here). Wine does not require Microsoft Windows, as it is a completely alternative implementation consisting of 100% open source Microsoft-free code, but it can optionally use native system DLLs if they are available. WINE's project leader and CodeWeavers' software engineer (a company which sells a modified WINE version), Alexandre Julliard, answers a series of questions to OSNews regarding the project and its future.